Calcining-furnace.



PATENTED JULY 31, 1906'.

T. A. EDISON. GALGINING FURNACE.

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- T. A. EDISON.

I 'GALGI-NING FURNACE.

APPLIUATION IILED JUL-2, 1902.

, PATENTED JULY 31. 1906.

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T. A; ;ED IS O;N. GALGINING FURNACE. APPLICATION FILED JAN. 1902.-

IATENTBD JULY 31, 1906.

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T. vA. EDISON.

CALGINING FURNAGE. APPLIOATIOHTILED 1w. 2, 1902.

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No. 827,089 PI'Q'BHTED JULY 31, 1906.

T- A. EDISON. I GAILCINING FURNACE. rrpwnmy rum: 3.211902;

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Attomgys UNITED STATES PATENT OFFICE v THOMAS A. EDISON, OF PARK, NEWJERSEY.

CALClNlNG-FURNACE.

Specification of Letters Patent.

latented July 31, 1906.

Application filed January 2. 1902. Serial No. 88,108.

- ing is a description.

My invention relates to improvements in calcining-furnaces, wh ch areparticularly designed for use in the burning of cementclinker, but whichcan be employed in other arts.

' My object is toprovide a relativel simple apparatus which shall bepractical y automatic in operation and wherein ,the desired material maybe burned, calcined, or incinerated efficiently and economically.

. To this end the invention comprises, first, one or more rotarycylindrical burners arranged, when a plurality are employed,preferablyin a horizontal bank, said burners being of novel constructionand operation ,second, means for automatically suppl ing pulverized fuelto each burner at one end for automaticallyintroducing the material tobe calcined or incinerated at the other end, and, fourth, suitableregenerative appliances by means of which a part of the heat in theburned material may be imparted to the air which enters the burner toeffect the combustion therein and a part of the heat which wouldotherwise be lost in the combustiongases may be conserved by effecting aan ther heating of such air.

The invention relates also to details of construction of many of thedevices constituting the apparatus-as, for example, of the bumersthemselves with the devices cooperating directl therewith, of thedevices for feeding the pu verized fuel to the burners, of the devicesfor feeding the unburned material to the burners, and of such other ofthe'elements of the apparatus as will be referred to more in" detailhereinafter.

Under the present practice the material is introduced intocement-burning kilns by gravity, the delivery-pi 6, being arranged at anangleto the longitu inal axis of the kiln and terminating at aconsiderable distance above the bottom thereof, so that the material isre uired to fall through the exit-gases, leaving t e kiln beforereaching the bottom. The delivery-pipe in "the, present kilns is heavilywater-jacketed in;. ord prothird, means .3; Fig. 5, a detail sectionalview tected from the very high temperature of the escaping gases. Owingto the low s ecific gravit of the unburned material, it settles very sowly along the bottom of the kiln, and

consequently a portion of the material will be carried out of the kilnwith the draft. A part of the'light unburned material which is thuscarried outwof the kiln passes u the stack with the draft and is lost,while t e remainder settles by its weight in the chamber beneath thestack and is allowed to accumulate in a dust-chamber, which requires tobe cleaned out from time to time. Thus the feeding of the unburnedmaterial under the present practice is wasteful and uneconomicaL; Withmy improved apparatus I force the unburned material into the upper endof the kiln by means of a suitable conveyor which is arrangedsubstantially parallel and close to the bottom of the kiln, so that thematerial has no opportunity to fall and create dust, but is p'ackedintothe kiln in successive increments. With kilns in which the escapinggases are at a relatively low temperature I find that it is notnecessary to water-jacket the conveyor-pipe, as it is sufficientlyprotected by the large bulk of cooled material constantly passingthrough it.

In order that the invention may be better I understood, attention isdirected to the accompanying drawings, forming part of thisspecification, and in which- Figure 1 is a plan view, partly in section,

showing three burners arran ed side by side and illustrating also thefee ing devices for one of said burners; Fig. 2, a side elevation,partly in section, of one of the burners; Fig. 3, an enlarged sectionalview through the rear end of one of the burners and showing also a partof the cooling-cylinder thereof; Fig. 4, a section taken at right an lesto Fig.

} illustrating the operation of the two guns for feeding the pulverizedfuel to each burner; Fig. 6, a

plan view of the devicesfor feeding the material to be calcined to thefeed-screws; Fig; 7,

a section on the' line 7 7 of Fig. 6; Fig. 8, a

section on the line 8 8 of Fig. 6; Fig. 9, a detail side elevationshowin the feedin mechanismfor feeding the pulverized fue. to the.

hoppers of the several feed-guns; Fig.v 10,18: detail end elevation ofthe'same; Fig. 11,13; vertical sectional viewillustrating, tworegenerators or hot stoveswliichmay' be emsployed in connectionwith-each burnerfor conserving a part of the heat of the combusand usedwith their respective burner.

In all ofthe above viewscorresponding parts are represented by the samenumerals of reference.

' 1 1 1 represent the rotary burners, preferably arranged in ahorizontal bank and each. supported on rollers 2, the thrust due to theinclination of these burners being received on a horizontal roller3 andthe burners being driven by suitable gearing 4.

Each burner is formed of a metallic shell 5 with a firebrick or otherrefractory lining 6. Each burner is preferably formed of a series ofsections of successively-reduced internal diam.-

-eter toward the u per end. At their upper smaller ends the urnersextend into brick chambers 7, from each of which leads a stack 8. I Attheir lower or larger ends each'burner extends into a chamber 9, made ofbrick.

Material is fed to each burner through .trou h 10, which is carried onwheels 11 and whic contains a screw conveyer 12, oper ated from asuitable motor 13, electric or otherwise. The trough is introducedthrough an opening in a partition 14 in the chamber 7, and the end ofsaid trough willtherefore actually proj ect within the burner, thetrough being substantially parallel with the axis of the" burner or kilnand close to the bottom thereof, so-that the material is packed into thekiln in successive increments without formation of dust: When eachtrough is full I of the relatively cold material, suflicie'nt radiatingcapacity is secured to prevent damage from the intense heat within theburner. When, however, the feed of material is stopped, the trough iswithdrawn, so as not to .be injured by the heat.

Each of the troughs 10 is provided with a hopper 15, having an open topof suflicient extent as to be capable of receiving material from afixedpoint of supply throughout a considerable range of movement of thetrough 101' The hopper 15 is supplied with the material to be calcinedor incinerated by any suitable arrangement of feeding devices. I prefer,however, to use an automatic feed,

which keeps the hoppers always supplied with the material and whichrequires absolutely no attention. .A convenient example a of asatisfactory feeding apparatus for this purpose is shown in Figs. 6, 7,and 8. Ex-

- tending into each of .the hoppers 15 of the feed-trough foreach'burner is a spout 16,

leading out of a conveyer-trough 1.7,,in which iwork-the flights 18 of ascraper ,con veyer of any suitable type. Leading to the trough of thescraper conve er at its receiving end is a chute 19,;supplie withmaterial from a belt conveyer-20', running under the bottom of asuitable storage-reservoir 21, which is kept s upplie'd withtheun'calcined material. Leadsupplies material to a chute 26. leadinginto 1 the supplyreservoir 21. I illustrate separate motors 27 fordriving the different conveyers referred to.

It will be seen that uncalcined material from the storage-reservoir 21will be conveyed by the conveyer 20 to the scraper conveyer, and by thelatter the-material will be scraped along the trough 17, droppingthrough the spouts 16 and filling the hoppers 1 5 of the feeding devicefor each burner. \iVhen the material piles up around the bottom of eachof the spouts 16, it will no longer flow out of the spout, which willtherefore become filled, so t at the material will be conveyed to thenext spout. Thus it will be seen that the feeding devices of the severalburners will be always kept automatically supplied with the desiredmaterial. Any surplus material which passes the spout 16 of the lastburner in the bank will be carried by the conveyers 23 and 25 back tothe reservoir 21. By making the hoppers 15 sufficiently extended thespouts 16 will always be maintained in engagement therewith irrespectiveof the position of the feeding mechanism, or instead it will be obviousthat said spouts might be flexible and connected directly to the troughs10.

' At the rear or larger end of each burner and leading into the chamber9 is a coolingcylinder 29, also mounted on rollersand suitably driven bypower. An inclined shelf directs the calcined material as it falls outof the bottom of each burner into the corresponding cooling-cylinder.Each coolingcylinder is provided at its rear end with a stationary backplate 31, having a flap 32 there-- in, and through which plate extendsthe discharge-pipe from a blower or fan 33. Mounted below the rear endof each cooling-cylinder is a conveyor 34 for removing the calcinedmaterial.

Mounted in the rear wall of the chamber 9, opposite the large endof eachburner, are the devices for feedii'ig-pulverized fuel to the same. Iemploy for this purpose a pair of pneumatic uns which project the fuelinto the burner by a series of successive puffs or impulses. These guns35 and 36 are tubular in form, tapering toward the forward ends, thelatter being protected by twyers 37, in which water circulates. The gunsare carried on a suitable turn-table 38 orare other. wise mounted sothat their axes can be varied with respect to that of each burner, aswill be explained. Leading into each of the guns, near the breechthereof, is a tube 39, communicating at its upper end withascre'wconvcyer 40. A piston 41 is arranged in each gun and is adapted.to reciprocate between the two extremes. (Shown in Fig. 5.) Each pistonworks between two sleeves 42, which can be removed when worn. Thepistons or plungers-41 extend rearwardly and are mounted in bearings 43,carriedon the turn-table 38, and each is connected by a link 44- ,withan arm 45 on a rock-shaft 46.

This rockshaftis oscillated by a link 47, con' nected with an arm 48 onthe rock-shaft, and 'at'its' other end with the wrist-pin on acrankdisk-49, the latter being mounted on a shaftforward stroke ofthepiston or plunger be at the rear portion of the burner.

forced into its respective barrel. A single valvechamber and valvecontrol the supply of compressed air to the two guns. This valvechamber53 (see Fig. 5) is provided with abalanced valve 54, in constantcommunicatiori with a compresjsed-air-supply ipe55, and which.successively uncovers the pipes 56 leading to the two guns. The valve 54is connected by a link 57 with one of the arms on the rock-shaft 46. r

In addition to employin the two guns 35 and 36, which are preferab yswiveled, as explained, I also prefer to make-use of a smallerceding-nozzle 58, water-jacketed at its forward end, supplied withpulverized fuel from a screw conveyer59 and havinga compressedair pipe60 opening in its breach for lowing a continuous stream of pulverizedfuel into the burner. This small auxiliary feedingnozzle is employed forthe pur ose of starting the combustion from a suitable wood fire; but italso may be continuously operated w en an additional heating effect isdesire The two guns 35 and 36 are'preferably so arranged that in oeration the fuel supplied by one ofthem wil be projected to a greater 7distance within the burner than the fuelsupplied by the other,-so thatthe combustion' zones of the two guns will overlap, as I describe inUnited States Letters Patent No. 759,357, granted May 10, 1904, wherebyI am enabled to secure a moreefficient clinkering effect than if suchcombustion zones were not partially coincident. This result may besecured either by placing one un above the other, as shown, or by sothrott ing' the air-pipe 56 ofone that its trajector will be less thanthat of the other. I pre er to mount the guns 35 and 36 so that theiraxes may be changed with respect to that of the burner in order that thepositionof the maximum-heat zone may be varied longitudinally oftheburner to suit the special conditions ofuse. Thus it will be seen thatif the guns are pointing directly parallel \vith the longitudinal axisof the burner the fuel will be projected to the maximum distancetherein, but that if the guns are moved to one side or the other to agreater or less extent the fuel will strike the side walls of theburner, and thereby be checked in its forward movement, thus causingthemaximunuheat zone to recede. In this way a very delicate and accurateadjust-- ment of the heat can be secured.

Fuel is fed to the conveyers 40 in any suitable way-as, for example,through the feedspouts 61, leading out of a long screw-conveyer trough62. This-conveyor is supplied with pulverized fuel from a supply be peror reservoir '63 at one end, and any surp us fuel is conveyed from theconveyer through a spout 64 to a return-conveyer 65, from which thesurplus fuel passes to an elevator 66 and by the'latter is returned tothe reservoir 63. The fuel fed along the conveyer 62 will fall throughthe spouts 61 and fill up the hoppers67 of the conveyers 40, whereu )onthe spouts 61 will themselves become filled, and the fuel will beprogressed on to the spouts beyond, any surplus returning to thereservoir, as will be understood. In this way the the guns andabsolutely no attention will be required in connection with the shine. Iillustrate the conveyers 40 as being driven from a small motor 68 on theturn-table 38.

In Figs. 11 and 12 I illustrate the preferred construction ofregenerative device which may be applied in connection with each burnerfor preventing loss of heat in the combustion-gases after they haveperformed the clinkering operation. Each regenerative device'comprises apair of regenerative'cylinders or hot stoves 69, made of cast rings orof boileriro'n, with a fire-brick lining 7 0. These cylinders arecarriedon suitable beams 71, e ther above or to one side of the chamber7 Leading from the chamber 7 is a flue 7 2, having branches 73communicating with the interior of each cylinder. The two cylinders 69are loosely filled with refractory material 74, preferably brokengranite of a size about four inches in diameter. Leading out of the topof each cylinder is a fine 75, connected with a fan or blower 76, each 0erated by a motor 77, preferably electric. hy reversing the direction ofrotation of the motors 77 the fans can be alternately used for blowersor exhausters, as'will be understood. Leading from the fines 73 arebranches 78, which communicate with a tunnel 79, preferably embedded inthe ground, so as to be insulated, and the en'd of which leads eitherinto the rear end of the cooler,29,' so as to take the lace of the pipefrom the fan 33,01 it may eaddirectly to the end ofjithe burner 1, asshown; Dampersor valves 80 are used for i cutting off the pipes 73 and 78, as will be evifuel will be automatically supplied to all of dent. Itwill be understood that when regenerative devices are employed;connecting with the chamber 7, the stack 8 will be dispenscd with. i

The operation of the device is as follows: A Wood-fire is first startedin' the burner and. pulverized coal is blown through the auxiliarynozzle 58 until the burner is Well started. Pulverizcd fuel is alsocontinuously supplied by the conveyor (52 to the hoppers 67 of theseveral guns, and by means of the fced scrcws 40 the tubes 89 of eachgun will be kept full of the material. The motor 52 being started, theshaft will be turned, oscillating the rock-shaft 46 and successivelywithdrawing the plungcrs 41 of each gun in the rear of the tubes 39 topermit the fuel to fall in front oftho withdrawn plunger. As the plungermoves forward the small charge of fuel will be forced into thegun-barrel. As the plunger 4-] of the upper-gun 36 moves forward (seeFig. 5) the valve 54 will dis close the airpipe 56 leading to that gun,and a charge of air will therefore enter the same and project the chargeof fuel into the burner. As the valve moves in the op posito directionit coincides with the forward movement of the piston of the other gun,in which the same operation is repeated. Thus the fuel will be fed tothe burners with a succession of impulses, which, as before stated, are

preferably so regulated that the fuel projected from one gunwill producea heat zone which overlaps that of the other gun. If de-' sired, theauxiliary nozzle 58 can be shut off, or when an increased heating effectat the lower end of the burner is desired the feed of fuel can becontinued througl'i said auxiliary nozzle. \Vhen. the burner has thusbeen started, cement material is continuously supplied to the hoppers 15of the several feeding devices, and the food-screws 12 thereof introducethe uncalcincd material into the upper end of the several burners, whichin rotating will cause the material to progress slowly toward itsloweror rear end through the intense heat of the burning fuel, therebyeffectively calcining the material. The burners 1 are very long, so thatbefore the fresh material reaches a zone of effective temper-a ture ithas the opportunity of robbing the combustion-gases passing to the stack8 of a portion of their heat, so as to thereby reduce the temperature ofsaid gases. After the material has been thus burned it drops out of thelow or end of the burners onto the shelf cined material is taken up bythis air, which consequently enters the burner in a highlyheated, andtherefore desirably efficient,

"condition. At the same time the calcined material Willi-be sufficientlycooled to enable .itto be transported safely by the conveyors 34. Whenregenerative devices are used at erating the fan of the former cylinderwill a be rotated to work the fan as an exhauster. the other fan beingworked asa blower. Ir

will thus be seen that the hot combustiongases from the burner Will bedrawn through one of the regenerative cylinders, so as to in tenselyheat the refractory material 74 therein. Air is being blown through theother cylinder, absorbing heat from the refractory material in the sameand passing through the tunnel 79 into the cooler 29, from whence itpasses into the burner. \Vhen the refractory material in theregenerative cylinder first referred to is sufficiently heated andtheheated refractory material in the other cylinder sufliciently cooled,the motors and dam pers are reversed, so that the products of coinbustion' will be directed through the second cylinder and air will beblown downwardly through the first cylinder. In this way the refractorymaterial in the two regenerative cylinders will be alternately heated bythe combustion-gases and cooled by air passing through the same on itsway to the lower end of the burner, as will be understood.

It will be observed that the apparatus as a whole is simple andefficient in construction, entirely automatic, and of relative economyof operation, since heat which is now lost in the combustion-gases isabsorbed by thefresh material passing through the upper portions of theburner, and heat which is now lost in the calcined material is retainedby being taken up by the air entering the burner, at its lower end.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. In a clinkering'or incinerating ap ara tus, the combination with alon slightly-inclined tubular burner, of a fee -trough extendin into thebore of said burner at its upper end and close to the bottom thereof,said trough being freely movable out of said burner in a horizontaldirection, a support for said trough in its in and out positions andmeans for forcing unburned material through said trough, substantiallyas set forth.

In a clinkering or incinerating ap aratus, the combination with a longslightly-ire clined tubular burner, of an open-top feedtrough extendinginto the bore of said burner at its upper end and close to the bottomthereof, said trough being freely movable out of said burner, a supportforsaid trough in its nand out posit1ons, a' conveyer in said trough,and means for sup lying unburned material to said trough, su stantiallyas set forth. I

3. In a olinkeringor incinerating ap aratus, the combination with a longshghtlfy-inclined tubular burner, of an open-top eedtrou 'h extendinginto the bore of said burner and eely movable entirely away from saidburner, a conveyer in said trough, a hopper above said conveyer, and aconveyer for su plying unburned materialto said trou h, t e open top ofsaid ho per being of su cient extent as to be capab e of receivingunburned said feed-trough being freely movable entirely awayfrom saidburner and stack-chamber in a horizontal direction, and means outside ofthe stack-chamber for supplying unburned material tosaid feed-trough,substantially as set forth.

5. In a clinkering or incinerating apparatus, the combination of a long,rotating, ap

proximately horizontal burner, means for supplying unburned material tothe same at its upper end, a pair of regenerative cylinders alternatellyconnected with the burner at its upper en means-for alternatelyconnectin said cylinders with the lower end of sai burner, and areversible fan connected with each of said cylinders for exhaustingco'mbustion gase's therefrom or blowing air therein, substantially asset forth.

6. In a clinkering or incinerating apparatus, the combination of a long,approximately horizontal, tubular burner, and a pluralityofneumatically-operated fuel-feedin devices or blowing ulverized fuel insai burner, said feeding evices being simultaneously adjustable withrespect to the longitudinal axis of the burner, substantially as setforth.

7. In a clinkering or incinerating apparatus, the combination of a long,approximately horizontal, tubular burner, a main pneumatic feedingdevice for blowing ulverized fuel into said burner, and an auxi iaryfeeding device for forcing a reduced charge of pulglerized fuel therein,substantially as set 8. In a clinkering or incinerating apparatus, thecombination of a long, approximately horizontal, tubular burner, a vmainpneumatic feeding device for blowing pulverized.

fuel into said burner, means for adjusting said feeding device withrespect to the longitudinal axis of the burner, and an auxiliary feedingdevice for forcing a reduced charge of ralit ulvi'ierized fuel therein,substantially asset ort 9. In a clinkering or incinerating apparatus,the combination of a long, approxi-' mately horizontal, tubular burner;a pneumatic feeding device for blowing-intermittent charges ofpulverized fuel into said burner, and an auxiliary feedim device forforcing a. continuous charge o l pulverized fuel therein, substantiallyas set forth.

10. In a clinkering or incinerating apparatus, the combination of along, approximately horizontal, tubular burner, a pair of fuel-feedingdevices swiveled with respect to the burner, and an auxiliarfuel-feeding device fixed in relation to sai burner, substantially asset forth.

1 1. In a clinkering or incinerating apparatus, the combination ofa lonap roximately horizontalburner, a plura ity 0 fuelfeedin'g devicesforfeeding pulverized fuel into said burners, means for operating saidfeeding devices so as to cause the heating zones derived therefrom tooverlap, and an auxiliary feedin device for forcing a reduced supply ofpulverized fuel into the burn er, substantially as set forth.

- 12. In a clinkering or incinerating appara-' tus, the combination of along, approximately horizontal, tubular burner, a. pluof fuel-feedingdevices for intermittent y feeding pulverized fuel into said burner,means for o crating said feeding devices so as to cause the heatingzones derived therefrom to overlap, and an auxiliary feeding device forforcing a continuous supply of pulverized fuel into the burner,substantially as set forth.

13. In a clinkering or incineratin apparatus, the combination of atubular urner, a feeding giin pointing into said burner, a plun-- gerfor directing successive charges of pulverized fuel into said gun, andmeans for admitting compressed air to the coincident with the o ierativestroke of said plunger, substantial y as set forth.

' 14. In a clinkering or incinerating apparatus, the combination of atubular burner, a pair of feeding-guns pointing into said burner,

a plunger for each gun, means for operating said plun ers inalternation, and means for successive y admitting compressed air to saidguns, substantially as set forth;

15. In a clinkering or incinerating apparatus, the combination of atubular burner, an intermittently-operating neumatic gun for projectingpulverized fue into said burner, and means for swiveling said gun,substantially as set forth.

16. In a clinkering or incinerating appara tus, the combination of atubular burner, an intermittently-operating neumatic un for projectingpulverized fue into said urner, means for swiveling said 11, and an."aux,- iliary fuel-feeding device for feeding fuel con lob Yerized fuelthereto, a plun er in each urn,

connections between said plungers, an an air-valve for admittingiairsuccessively to the guns, substantially as set forth.

18.- In. an apparatus of the character described, a feed-trough mountedon wheels and" carrfi ing a conveyor and a -1notor for 'drivingt esamewhereby all may be moved together, substantially as set forth.

.-1'9; -In apparatusfor burning, Portland cement, the] combination withY a sli'ghtly-in-. cl-inedrotary tubular-kiln, of a'snbstantially.horizontal conyeyerfor forcibly introducing material into the kiln" atits upperend, thesmgoso delivery end of said conveyer being adjacent tothe bottom of the kiln, substantially as set forth. 7

20. In apparatus for burning Portland ce- 'ment, the combination with along rotary kiln, and a stack-chamber at the upper end thereof forcarrying off the products of combustion, of a conveyer extending throughsaid stack-chamber approximatel-yv parallel with the longitudinal axisofthe kiln for introducing material into the kiln and with its deliveryend adjacent to the bottom of the kiln, substantially as set-forth.

This specification signed and witnessed this 24th day 04 December, 1901.

THOMAS A. EDISON.

Witnesses:

FRANK L. DYER, J. F. RANDOLPH.

